Platelet-rich fibrin (PRF) has been widely used owing to its ability to stimulate tissue regeneration. To date, few studies have described the antibacterial properties of PRF. Previously, PRF prepared by horizontal centrifugation (H-PRF) was shown to contain more immune cells than leukocyte- and platelet-rich fibrin (L-PRF). This study aimed to compare the antimicrobial effects of PRFs against Staphylococcus aureus and Escherichia coli in vitro and to determine whether the antibacterial effects correlated with the number of immune cells. Blood samples were obtained from eight healthy donors to prepare L-PRF and H-PRF. The sizes and weights of L-PRF and H-PRF were first evaluated, and their antibacterial effects against S. aureus and E. coli were then tested in vitro using the inhibition ring and plate-counting test methods. Flow-cytometric analysis of the cell components of L-PRF and H-PRF was also performed. No significant differences in size or weight were observed between the L-PRF and H-PRF groups. The H-PRF group contained more leukocytes than the L-PRF group. While both PRFs had notable antimicrobial activity against S. aureus and E. coli, H-PRF demonstrated a significantly better antibacterial effect than L-PRF. Furthermore, the antimicrobial ability of the PRF solid was less efficient than that of wet PRF. In conclusion, H-PRF exhibited better antibacterial activity than L-PRF, which might have been attributed to having more immune cells.

富含血小板的纤维蛋白（PRF）由于其刺激组织再生的能力而被广泛使用。迄今为止，很少有研究描述PRF的抗菌特性。以前，通过水平离心（H-PRF）制备的PRF被证明比富含白细胞和富含血小板的纤维蛋白（L-PRF）包含更多的免疫细胞。这项研究旨在比较PRFs对金黄色葡萄球菌和大肠杆菌的体外抗菌作用，并确定抗菌作用是否与免疫细胞数量相关。从八位健康供体中获取血液样本以制备L-PRF和H-PRF。首先评估L-PRF和H-PRF的大小和重量，以及它们对金黄色葡萄球菌和大肠杆菌的抗菌作用然后使用抑制环和计数板的测试方法进行体外测试。还对L-PRF和H-PRF的细胞成分进行了流式细胞分析。L-PRF和H-PRF组之间没有观察到大小或重量的显着差异。H-PRF组比L-PRF组包含更多的白细胞。尽管两种PRF对金黄色葡萄球菌和大肠杆菌均具有显着的抗菌活性，但H-PRF的抗菌效果明显优于L-PRF。此外，PRF固体的抗微生物能力不如湿PRF有效。总之，H-PRF比L-PRF表现出更好的抗菌活性，这可能归因于拥有更多的免疫细胞。